Gene therapy for amyotrophic lateral sclerosis and other spinal cord disorders

ABSTRACT

This disclosure provides methods and compositions for treating disorders or injuries that affect motor function and control in a subject. In one aspect, the invention a transgene product is delivered to a subject’s spinal cord by administering a recombinant neurotrophic viral vector containing the transgene to the brain. The viral vector delivers the transgene to a region of the brain which is susceptible to infection by the virus and which expresses the encoded recombinant viral gene product. Also provided are compositions for delivery of a transgene product to a subject’s spinal cord by administering a recombinant neurotrophic viral vector containing the transgene to the subject’s brain.

FIELD OF THE INVENTION

The present invention relates to compositions and methods for treatingdisorders affecting a subject’s motor function and in particular, motorfunction affected by disease or injury to the brain and/or spinal cord.

Gene therapy is an emerging treatment modality for disorders affectingthe central nervous system (CNS). CNS gene therapy has been facilitatedby the development of viral vectors capable of effectively infectingpost-mitotic neurons. The central nervous system is made up of thespinal cord and the brain. The spinal cord conducts sensory informationfrom the peripheral nervous system to the brain and conducts motorinformation from the brain to various effectors. For a review of viralvectors for gene delivery to the central nervous system, see Davidson etal. (2003) Nature Rev. 4:353-364.

Adeno-associated virus (AAV) vectors are considered useful for CNS genetherapy because they have a favorable toxicity and immunogenicityprofile, are able to transduce neuronal cells, and are able to mediatelong-term expression in the CNS (Kaplitt et al. (1994) Nat. Genet.8:148-154; Bartlett et al. (1998) Hum. Gene Ther. 9:1181-1186; andPassini et al. (2002) J. Neurosci. 22:6437-6446).

One useful property of AAV vectors lies in the ability of some AAVvectors to undergo retrograde and/or anterograde transport in neuronalcells. Neurons in one brain region are interconnected by axons to distalbrain regions thereby providing a transport system for vector delivery.For example, an AAV vector may be administered at or near the axonterminals of neurons. The neurons internalize the AAV vector andtransport it in a retrograde manner along the axon to the cell body.Similar properties of adenovirus, HSV, and pseudo-rabies virus have beenshown to deliver genes to distal structures within the brain (Soudas etal. (2001) FASEB J. 15:2283-2285; Breakefield et al. (1991) New Biol.3:203-218; and deFalco et al. (2001) Science, 291:2608-2613).

Several groups have reported that the transduction of the brain by AAVserotype 2 (AAV2) is limited to the intracranial injection site (Kaplittet al. (1994) Nat. Genet. 8:148-154; Passini et al. (2002) J. Neurosci.22:6437-6446; and Chamberlin et al. (1998) Brain Res. 793:169-175).Recent reports suggest that retrograde axonal transport of neurotrophicviral vectors can also occur in select circuits of the normal rat brain(Kaspar et al. (2002) Mol. Ther. 5:50-56 (AAV vector); Kasper et al.(2003) Science 301:839-842 (lentiviral vector) and Azzouz et al. (2004)Nature 429:413-417 (lentiviral vector). Roaul et al. (2005) Nat. Med.11(4):423-428 and Ralph et al. (2005) Nat. Med. 11(4):429-433 reportthat intramuscular injection of lentivirus expressing silencing humanCu/Zn supreoxide dismutase (SOD1) interfering RNA retarded disease onsetof amyotrophic lateral sclerosis (ALS) in a therapeutically relevantrodent model of ALS.

Cells transduced by AAV vectors may express a therapeutic transgeneproduct, such as an enzyme or a neurotrophic factor, to mediatebeneficial effects intracellularly. These cells may also secrete thetherapeutic transgene product, which may be subsequently taken up bydistal cells where it may mediate its beneficial effects. This processhas been described as cross-correction (Neufeld et al. (1970) Science169:141-146).

However, a need still exists for compositions and methods to treatdysfunction of the spinal cord that result in loss of motor function inhuman patients. This invention satisfies this need and provides relatedadvantages as well.

SUMMARY OF THE INVENTION

This invention provides methods and compositions to deliver a transgeneto the spinal cord and/ or the brainstem region of a subject byintraventricular administration of a recombinant neurotrophic viralvector containing an IGF-1 transgene. The viral delivery may be underconditions that favor expression of the transgene in ependymal cells.

This invention provides methods and compositions to deliver a transgeneto the spinal cord and/ or the brainstem region of a subject byintraventricular administration of a recombinant neurotrophic viralvector comprising a transgene selected from the group consisting ofinsulin growth factor-1 (IGF-1), calbindin D28K, parvalbumin,HIF1-alpha, SIRT-2, VEGF, SMN-1, SMN-2, CNTF (Ciliary neurotrophicfactor), sonic hedgehog (shh), erythropoietin (EPO), lysyl oxidase(LOX), progranulin, prolactin, ghrelin, neuroserpin, angiogenin, andplacenta lactogen. The viral delivery may be under conditions that favorexpression of the transgene in ependymal cells.

This invention provides methods and compositions to deliver a transgeneto the spinal cord and/ or the brainstem region of a subject byintraventricular (known also as intracerebroventricular or ICV)administration of a recombinant neurotrophic viral vector comprising atleast two transgenes selected from the group consisting of insulingrowth factor-1 (IGF-1), calbindin D28K, parvalbumin, HIF1-alpha,SIRT-2, VEGF, SMN-1, SMN-2, CNTF (Ciliary neurotrophic factor), sonichedgehog (shh), erythropoietin (EPO), lysyl oxidase (LOX), progranulin,prolactin, ghrelin, neuroserpin, angiogenin, and placenta lactogen. Inone embodiment, a recombinant adeno-associated viral vector comprisesIGF-1 and VEGF. The viral delivery may be under conditions that favorexpression of the transgene in ependymal cells. Tables 1-3 providepotential combinations of transgene pairs useful in the instantinvention.

In a further aspect, the invention provides compositions and method toameliorate the symptoms of a motor neuron disorder in a subject byadministering a recombinant neurotrophic viral vector containing thetherapeutic transgene to the subject’s brain and under conditions thatfavor expression of the transgene in a therapeutically effective amount.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention as claimed.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows Kaplan-Meier survival curves comparing intraventricularadministration of AAV4 encoding beta-galactosidase to AAV4 encodingIGF1. A significant difference in survival was observed. Recipients wereSOD mice.

FIG. 2 shows a comparison of forelimb strength between SOD mice whichreceived intraventricular administration of AAV4 encodingbeta-galactosidase (Lac Z) versus AAV4 encoding IGF1. IGF1 recipientslost strength more gradually and more slowly.

FIG. 3 shows a comparison of hindlimb strength between SOD mice whichreceived intraventricular administration of AAV4 encodingbeta-galactosidase (Lac Z) versus AAV4 encoding IGF1. IGF1 recipientslost strength more gradually and later.

FIG. 4 shows a comparison of rotarod (latency to fall) between SOD micewhich received intraventricular administration of AAV4 encodingbeta-galactosidase (Lac Z) versus AAV4 encoding IGF1. IGF1 recipientsdeclined more gradually and later.

FIG. 5 shows a comparison of loss of body mass between SOD mice whichreceived intraventricular administration of AAV4 encodingbeta-galactosidase (Lac Z) versus AAV4 encoding IGF1. IGF1 recipientslost body mass more gradually and later.

FIG. 6 shows a comparison of GFAP staining in the brainstem of SOD micethat received intraventricular administration of AAV4 encodingbeta-galactosidase (Bgal) versus AAV4 encoding IGF1. As evidenced by thereduced GFAP staining in the AAV4-IGF1 treated mice, intraventriculardelivery of AAV4-IGF-1 led to a reduction in astrogliosis within thebrainstem.

FIG. 7 shows a comparison of GFAP staining in the ventral spinal cord ofSOD mice that received intraventricular administration of AAV4 encodingbeta-galactosidase (Bgal) versus AAV4 encoding IGF1. As evidenced by thereduced GFAP staining in the AAV4-IGF1 treated mice, intraventriculardelivery of AAV4-IGF-1 led to a reduction in astrogliosis in the ventralspinal cord.

FIG. 8 shows a comparison of nitrotyrosine levels in SOD mice thatreceived intraventricular administration of AAV4 encodingbeta-galactosidase (Bgal) versus AAV4 encoding IGF1., As evidenced bythe reduced staining in the AAV4-IGF1 treated mice, intraventriculardelivery of AAV4-IGF-1 led to a reduction in nitrotyrosine levelsthroughout the spinal cord e.g., cervical, thoracic, lumbar, and sacralregions.

FIG. 9 shows green fluorescent protein (GFP) expression in mice treatedwith AAV4-GFP. GFP is distributed in the ependymal cell layer of theventricular system following intraventricular delivery of AAV4-GFP.

FIG. 10 shows green fluorescent protein (GFP) expression in mice treatedwith AAV4-GFP. GFP is distributed in the ependymal cell layer of thespinal cord central canal following intraventricular delivery ofAAV4-GFP.

FIG. 11A shows the results of RT-PCR performed on tissues of SOD micethat were treated by intraventricular injection of AAV4-IGF-1. B-Actinwas measured as an internal control. Vector was detected throughout thecortex, brainstem, and spinal cord following intraventricular delivery.FIG. 11B shows the results of RT-PCR performed on tissues of SOD micethat were treated by intraventricular injection of AAV4-VEGF. B-Actinwas measured as an internal control. Vector was detected throughout thecortex, brainstem, and spinal cord following intraventricular deliveryof AAV4-VEGF.

FIG. 12 shows Kaplan-Meier survival curves of SOD1 mice that receivedintraventricular administration of AAV4 encoding green fluorescentprotein (GFP) or AAV4 encoding VEGF165. A significant increase in mediansurvival was observed in mice receiving AAV4-VEGF.

FIG. 13 shows a comparison of rotarod (latency to fall) between SOD micethat received intraventricular administration of AAV4 encoding GFPversus AAV4 encoding VEGF165. VEGF165 recipients declined more graduallyand later. FIG. 13 also shows a comparison of hindlimb strength betweenSOD mice that received intraventricular administration of AAV4 encodingGFP versus AAV4 encoding VEGF165. VEGF165 recipients lost strength moregradually and later.

Tables 1-3 provide a number of potential gene pairs for use in theinstant invention where the embodiment utilizes more than one gene.

DETAILED DESCRIPTION OF THE INVENTION

In order that the present invention may be more readily understood,certain terms are first defined. Additional definitions are set forththroughout the detailed description.

The practice of the present invention will employ, unless otherwiseindicated, conventional techniques of immunology, molecular biology,microbiology, cell biology and recombinant DNA, which are within theskill of the art. See, e.g., Sambrook, Fritsch and Maniatis, MOLECULARCLONING: A LABORATORY MANUAL, 2^(nd) edition (1989); CURRENT PROTOCOLSIN MOLECULAR BIOLOGY (F. M. Ausubel, et al. eds., (1987)); the seriesMETHODS IN ENZYMOLOGY (Academic Press, Inc.): PCR 2: A PRACTICALAPPROACH (M.J. MacPherson, B.D. Hames and G.R. Tayloreds. (1995)),Harlow and Lane, eds. (1988) ANTIBODIES, A LABORATORY MANUAL, and ANIMALCELL CULTURE (R.I. Freshney, ed. (1987)).

As used in the specification and claims, the singular form “a”, “an” and“the” include plural references unless the context clearly dictatesotherwise. For example, the term “a cell” includes a plurality of cells,including mixtures thereof.

As used herein, the term “comprising” is intended to mean that thecompositions and methods include the recited elements, but not excludingothers. “Consisting essentially of” when used to define compositions andmethods, shall mean excluding other elements of any essentialsignificance to the combination. Thus, a composition consistingessentially of the elements as defined herein would not exclude tracecontaminants from the isolation and purification method andpharmaceutically acceptable carriers, such as phosphate buffered saline,preservatives, and the like. “Consisting of” shall mean excluding morethan trace elements of other ingredients and substantial method stepsfor administering the compositions of this invention. Embodimentsdefined by each of these transition terms are within the scope of thisinvention.

All numerical designations, e.g., pH, temperature, time, concentration,and molecular weight, including ranges, are approximations which arevaried (+) or (-) by increments of 0.1. It is to be understood, althoughnot always explicitly stated that all numerical designations arepreceded by the term “about”. It also is to be understood, although notalways explicitly stated, that the reagents described herein are merelyexemplary and that equivalents of such are known in the art.

The term “transgene” refers to a polynucleotide that is introduced intoa cell of and is capable of being transcribed into RNA and optionally,translated and/or expressed under appropriate conditions. In one aspect,it confers a desired property to a cell into which it was introduced, orotherwise leads to a desired therapeutic or diagnostic outcome.

The terms “genome particles (gp),” or “genome equivalents,” or “genomecopies” (gc) as used in reference to a viral titer, refer to the numberof virions containing the recombinant AAV DNA genome, regardless ofinfectivity or functionality. The number of genome particles in aparticular vector preparation can be measured by procedures such asdescribed in the Examples herein, or for example, in Clark et al. (1999)Hum. Gene Ther., 10:1031-1039; Veldwijk et al. (2002) Mol. Ther.,6:272-278.

The terms “infection unit (iu),” “infectious particle,” or “replicationunit,” as used in reference to a viral titer, refer to the number ofinfectious and replication-competent recombinant AAV vector particles asmeasured by the infectious center assay, also known as replicationcenter assay, as described, for example, in McLaughlin et al. (1988) J.Virol., 62:1963-1973.

The term “transducing unit (tu)” as used in reference to a viral titer,refers to the number of infectious recombinant AAV vector particles thatresult in the production of a functional transgene product as measuredin functional assays such as described in Examples herein, or forexample, in Xiao et al. (1997) Exp. Neurobiol., 144:113-124; or inFisher et al. (1996) J. Virol., 70:520-532 (LFU assay).

The terms “therapeutic,” “therapeutically effective amount,” and theircognates refer to that amount of an RNA, DNA or expression product ofDNA and/or RNA that results in prevention or delay of onset oramelioration of symptoms of in a subject or an attainment of a desiredbiological outcome, such as correction of neuropathology, e.g., cellularpathology associated with a motor neuronal disease such as ALS. The term“therapeutic correction” refers to that degree of correction thatresults in prevention or delay of onset or amelioration of symptoms in asubject. The effective amount can be determined by known empiricalmethods.

A “composition” is also intended to encompass a combination of activeagent and another carrier, e.g., compound or composition, inert (forexample, a detectable agent or label) or active, such as an adjuvant,diluent, binder, stabilizer, buffers, salts, lipophilic solvents,preservative, adjuvant or the like. Carriers also include pharmaceuticalexcipients and additives proteins, peptides, amino acids, lipids, andcarbohydrates (e.g., sugars, including monosaccharides, di-, tri-,tetra-, and oligosaccharides; derivatized sugars such as alditols,aldonic acids, esterified sugars and the like; and polysaccharides orsugar polymers), which can be present singly or in combination,comprising alone or in combination 1-99.99% by weight or volume.Exemplary protein excipients include serum albumin such as human serumalbumin (HSA), recombinant human albumin (rHA), gelatin, casein, and thelike. Representative amino acid/antibody components, which can alsofunction in a buffering capacity, include alanine, glycine, arginine,betaine, histidine, glutamic acid, aspartic acid, cysteine, lysine,leucine, isoleucine, valine, methionine, phenylalanine, aspartame, andthe like. Carbohydrate excipients are also intended within the scope ofthis invention, examples of which include but are not limited tomonosaccharides such as fructose, maltose, galactose, glucose,D-mannose, sorbose, and the like; disaccharides, such as lactose,sucrose, trehalose, cellobiose, and the like; polysaccharides, such asraffinose, melezitose, maltodextrins, dextrans, starches, and the like;and alditols, such as mannitol, xylitol, maltitol, lactitol, xylitolsorbitol (glucitol) and myoinositol.

The term carrier further includes a buffer or a pH adjusting agent;typically, the buffer is a salt prepared from an organic acid or base.Representative buffers include organic acid salts such as salts ofcitric acid, ascorbic acid, gluconic acid, carbonic acid, tartaric acid,succinic acid, acetic acid, or phthalic acid; Tris, tromethaminehydrochloride, or phosphate buffers. Additional carriers includepolymeric excipients/additives such as polyvinylpyrrolidones, ficolls (apolymeric sugar), dextrates (e.g., cyclodextrins, such as2-hydroxypropyl-.quadrature.-cyclodextrin), polyethylene glycols,flavoring agents, antimicrobial agents, sweeteners, antioxidants,antistatic agents, surfactants (e.g., polysorbates such as “TWEEN 20”and “TWEEN 80”), lipids (e.g., phospholipids, fatty acids), steroids(e.g., cholesterol), and chelating agents (e.g., EDTA).

As used herein, the term “pharmaceutically acceptable carrier”encompasses any of the standard pharmaceutical carriers, such as aphosphate buffered saline solution, water, and emulsions, such as anoil/water or water/oil emulsion, and various types of wetting agents.The compositions also can include stabilizers and preservatives and anyof the above noted carriers with the additional provision that they beacceptable for use in vivo. For examples of carriers, stabilizers andadjuvants, see Martin REMINGTON’S PHARM. SCI., 15th Ed. (Mack Publ. Co.,Easton (1975) and Williams & Williams, (1995), and in the “PHYSICIAN’SDESK REFERENCE”, 52^(nd) ed., Medical Economics, Montvale, N.J. (1998).Carriers may also comprise artificial cerebrospinal fluid (aCSF).

A “subject,” “individual” or “patient” is used interchangeably herein,which refers to a vertebrate, preferably a mammal, more preferably ahuman. Mammals include, but are not limited to, murines, rats, simians,humans, farm animals, sport animals, and pets.

A “control” is an alternative subject or sample used in an experimentfor comparison purpose. A control can be “positive” or “negative.” Forexample, where the purpose of the experiment is to determine acorrelation of an altered expression level of a gene with a particulartype of pathology (see ALS, for example, infra), it is generallypreferable to use a positive control (a subject or a sample from asubject, carrying such alteration and exhibiting symptoms characteristicof that disease), and a negative control (a subject or a sample from asubject lacking the altered expression and clinical symptom of thatdisease).

“Differentially expressed” as applied to a gene, refers to thedifferential production of the mRNA transcribed from the gene or theprotein product encoded by the gene. A differentially expressed gene maybe overexpressed or underexpressed as compared to the expression levelof a normal or control cell. In one aspect, it refers to a differentialthat is at least 1.5 times, or at least 2.5 times, or alternatively atleast 5 times, or alternatively at least 10 times higher or lower thanthe expression level detected in a control sample. The term“differentially expressed” also refers to nucleotide sequences in a cellor tissue which are expressed where silent in a control cell or notexpressed where expressed in a control cell.

As used herein, the term “modulate” means to vary the amount orintensity of an effect or outcome, e.g., to enhance, augment, diminishor reduce.

As used herein the term “ameliorate” is synonymous with “alleviate” andmeans to reduce or lighten. For example one may ameliorate the symptomsof a disease or disorder by making them more bearable.

For identification of structures in the human brain, see, e.g., TheHuman Brain: Surface, Three-Dimensional Sectional Anatomy With MRI, andBlood Supply, 2nd ed., eds. Deuteron et al., Springer Vela, 1999; Atlasof the Human Brain, eds. Mai et al., Academic Press; 1997; and Co-PlanarStereotaxic Atlas of the Human Brain: 3-Dimensional Proportional System:An Approach to Cerebral Imaging, eds. Tamarack et al., Thyme MedicalPub., 1988. For identification of structures in the mouse brain, see,e.g., The Mouse Brain in Stereotaxic Coordinates, 2nd ed., AcademicPress, 2000.

Intracerebroventricular, or intraventricular, delivery of a recombinantviral vector may be performed in any one or more of the brain’sventricles, which are filled with cerebrospinal fluid (CSF). CSF is aclear fluid that fills the ventricles, is present in the subarachnoidspace, and surrounds the brain and spinal cord. CSF is produced by thechoroid plexuses and via the weeping or transmission of tissue fluid bythe brain into the ventricles. The choroid plexus is a structure liningthe floor of the lateral ventricle and the roof of the third and fourthventricles. Certain studieshave indicated that these structures arecapable of producing 400-600 ccs of fluid per day consistent with anamount to fill the central nervous system spaces four times in a day. Inadults, the volume of this fluid has been calculated to be from 125 to150 ml (4-5 oz). The CSF is in continuous formation, circulation andabsorption. Certain studies have indicated that approximately 430 to 450ml (nearly 2 cups) of CSF may be produced every day. Certaincalculations estimate that production equals approximately 0.35 ml perminute in adults and 0.15 per minute in infants. The choroid plexuses ofthe lateral ventricles produce the majority of CSF. It flows through theforamina of Monro into the third ventricle where it is added to byproduction from the third ventricle and continues down through theaqueduct of Sylvius to the fourth ventricle. The fourth ventricle addsmore CSF; the fluid then travels into the subarachnoid space through theforamina of Magendie and Luschka. It then circulates throughout the baseof the brain, down around the spinal cord and upward over the cerebralhemispheres. The CSF empties into the blood via the arachnoid villi andintracranial vascular sinuses.

In aspects where gene transfer is mediated by a DNA viral vector, suchas an adenovirus (Ad) or adeno-associated virus (AAV), a vectorconstruct refers to the polynucleotide comprising the viral genome orpart thereof, and a transgene. Adenoviruses (Ads) are a relatively wellcharacterized, homogenous group of viruses, including over 50 serotypes.See, e.g., International PCT Application No. WO 95/27071. Ads are easyto grow and do not require integration into the host cell genome.Recombinant Ad derived vectors, particularly those that reduce thepotential for recombination and generation of wild-type virus, have alsobeen constructed. See, International PCT Application Nos. WO 95/00655and WO 95/11984. Wild-type AAV has high infectivity and specificityintegrating into the host cell’s genome. See, Hermonat and Muzyczka(1984) Proc. Natl. Acad. Sci. USA 81:6466-6470 and Lebkowski, et al.(1988) Mol. Cell. Biol. 8:3988-3996.

In one aspect, the invention provides a method to deliver a transgene tothe brain of a subject by intraventricular administration of arecombinant neurotrophic viral vector containing the IGF-1 transgene.The delivery is under conditions that favor expression of the transgenein ependymal cells.

In another aspect, the invention provides a method of delivering atherapeutic transgene product to a target cell of the CNS, which is aneuron or a glial cell, in a mammal afflicted with a motor neuronaldisorder, e.g., ALS or traumatic spinal cord injury, where the transgenemay be IGF-1. The transgene can be administered via a neurotrophicvirus. The virus can be administered via the ventricles. Ependymal cellsmay be transduced to express the transgene and secrete the encodedprotein product.

In an alternate embodiment, the invention is a method to treat a motorneuron disorder in a subject by intraventricular administration of arecombinant neurotrophic viral vector containing a therapeutic transgeneto the brain of the subject, wherein the transgene is expressed in atherapeutically effective amount in the subject.

This invention also is a method to ameliorate the symptoms of a motorneuron disorder in a subject by intraventricular administration of arecombinant neurotrophic viral vector containing a therapeutic transgeneto the brain, wherein said transgene is expressed in a therapeuticallyeffective amount in the subject.

Suitable neurotrophic viral vectors for the practice of this inventioninclude, but are not limited to adeno-associated viral vectors (AAV),herpes simplex viral vectors (U.S. Pat. No. 5,672,344) and lentiviralvectors.

In the methods of the invention, AAV of any serotype can be used. Theserotype of the viral vector used in certain embodiments of theinvention is selected from the group consisting from AAV1, AAV2, AAV3,AAV4, AAV5, AAV6, AAV7, and AAV8 (see, e.g., Gao et al. (2002) PNAS,99:11854-11859; and Viral Vectors for Gene Therapy: Methods andProtocols, ed. Machida, Humana Press, 2003). Other serotype besidesthose listed herein can be used. Furthermore, pseudotyped AAV vectorsmay also be utilized in the methods described herein. Pseudotyped AAVvectors are those which contain the genome of one AAV serotype in thecapsid of a second AAV serotype; for example, an AAV vector thatcontains the AAV2 capsid and the AAV1 genome or an AAV vector thatcontains the AAV5 capsid and the AAV 2 genome (Auricchio et al., (2001)Hum. Mol. Genet., 10(26):3075-81).

AAV vectors are derived from single-stranded (ss) DNA parvoviruses thatare nonpathogenic for mammals (reviewed in Muzyscka (1992) Curr. Top.Microb. Immunol., 158:97-129). Briefly, recombinant AAV-based vectorshave the rep and cap viral genes that account for 96% of the viralgenome removed, leaving the two flanking 145-basepair (bp) invertedterminal repeats (ITRs), which are used to initiate viral DNAreplication, packaging and integration. In the absence of helper virus,wild-type AAV integrates into the human host-cell genome withpreferential site-specificity at chromosome 19q 13.3 or it may bemaintained episomally. A single AAV particle can accommodate up to 5 kbof ssDNA, therefore leaving about 4.5 kb for a transgene and regulatoryelements, which is typically sufficient. However, trans-splicing systemsas described, for example, in U.S. Pat. No. 6,544,785, may nearly doublethis limit.

In an illustrative embodiment, AAV is AAV4. Adeno-associated virus ofmany serotypes, especially AAV2, have been extensively studied andcharacterized as gene therapy vectors. Those skilled in the art will befamiliar with the preparation of functional AAV-based gene therapyvectors. Numerous references to various methods of AAV production,purification and preparation for administration to human subjects can befound in the extensive body of published literature (see, e.g., ViralVectors for Gene Therapy: Methods and Protocols, ed. Machida, HumanaPress, 2003). Additionally, AAV-based gene therapy targeted to cells ofthe CNS has been described in U.S. Patent Nos. 6,180,613 and 6,503,888.Additional exemplary AAV vectors are recombinant AAV2/1, AAV2/2, AAV2/5,AAV2/7 and AAV2/8 serotype vectors encoding human protein.

In certain methods of the invention, the vector comprises a transgeneoperably linked to a promoter. The transgene encodes a biologicallyactive molecule, expression of which in the CNS results in at leastpartial correction of neuropathology and/or stabilization of diseaseprogression. The transgene may be insulin growth factor-1 (IGF-1),calbindin D28, parvalbumin, HIF1-alpha, SIRT-2, VEGF, SMN-1, SMN-2, CNTF(Ciliary neurotrophic factor), sonic hedgehog (shh), erythropoietin(EPO), lysyl oxidase (LOX), progranulin, prolactin, ghrelin,neuroserpin, angiogenin, and placenta lactogen.

In certain methods of the invention, the vector comprises more than onetransgene, wherein each transgene is operably linked to a promoter toenable the expression of more than one trangene from a single AAVvector. In additional methods, the transgenes may be operably linked tothe same promoter. Each transgene encodes a biologically activemolecule, expression of which in the CNS results in at least partialcorrection of neuropathology. Additionally, in cases where more than onetransgene is delivered, the transgenes may be delivered via more thanone AAV vector, wherein each AAV vector comprises a transgene operablylinked to a promoter. The transgenes may be selected from the groupconsisiting of: insulin growth factor-1 (IGF-1), calbindin D28,parvalbumin, HIF1-alpha, SIRT-2, VEGF, SMN-1, SMN-2, CNTF (Ciliaryneurotrophic factor), sonic hedgehog (shh), erythropoietin (EPO), lysyloxidase (LOX), progranulin, prolactin, ghrelin, neuroserpin, andplacenta lactogen. For example, the transgenes may comprise VEGF, suchas VEGF165, and IGF-1.

The insulin-like growth factor (IGF-1) gene has a complex structure,which is well-known in the art. It has at least two alternativelyspliced mRNA products arising from the gene transcript. There is a 153amino acid peptide, known by several names including IGF-1A or IGF-1 Ea,and a 195 amino acid peptide, known by several names including IGF-1B orIGF-1Eb. The Eb form may also be known as Ec in humans. The mature formof IGF-1 is a 70 amino acid polypeptide. Both IGF-1 Ea and IGF-1 Ebcontain the 70 amino acid mature peptide, but differ in the sequence andlength of their carboxyl-terminal extensions. The peptide sequences ofIGF-1 Ea and IGF-1 Eb are represented by SEQ ID NOS: 1 and 2,respectively. The genomic and functional cDNAs of human IGF-1, as wellas additional information regarding the IGF-1 gene and its products, areavailable at Unigene Accession No. NM_00618. The IGF-1 protein may havethe sequence shown in SEQ ID NO: 3 or allelic variants thereof. Allelicvariants may differ by a single or a small number of amino acidresidues, typically less than 5, less than 4, less than 3 residues. TheIGF-1 protein sequence may be modified to contain the TAT transductiondomain (YGRKKRRQRRR )as shown in SEQ ID NO: 4.

Although their functions are not fully known, calbindin D28K (alsoreferred to as calbindin D28) and parvalbumin are calcium-bindingproteins theorized to be involved in calcium buffering. Without beinglimited as to theory, there is evidence to suggest that calciumhomeostasis is altered in subjects with ALS. There is evidence tosuggest that low levels of calbindin-D28K and/or parvalbumin mayincrease the vulnerability of motor neurons in ALS by reducing theirability to handle an increased calcium load. This reduction may lead tocell injury and eventual motor neuron death. Further evidence suggeststhat neurons rich in calcium-binding proteins, such as calbindin D28Kand parvalbumin, are resistant to degeneration.

HIF-1 is a heterodimeric protein composed of two subunits: (i) aconstitutively expressed beta (β) subunit also known as aryl hydrocarbonnuclear translocator (ARNT) (which is shared by other relatedtranscription factors (e.g., the dioxin/aryl hydrocarbon receptor(DR/AhR)); and (ii) an alpha (α) subunit (see, e.g., WO 96/39426,International Application No. PCT/US96/10251 describing the recentaffinity purification and molecular cloning of HIF-1α) whoseaccumulation is regulated by a post-translational mechanism such thathigh levels of the alpha subunit can only be detected during hypoxicconditions. Both subunits are members of the basic helix-loop-helix(bHLH)-PAS family of transcription factors. These domains regulate DNAbinding and dimerization. The transactivation domain resides in theC-terminus of the protein. The basic region consists of approximately 15predominantly basic amino acids responsible for direct DNA binding. Thisregion is adjacent to two amphipathic a helices, separated by a loop ofvariable length, which forms the primary dimerization interface betweenfamily members (Moore, A.W., et al., Proc. Natl. Acad. Sci. USA97:10436-41 (2000)). The PAS domain, which is named after the firstthree proteins in which it was identified (Per, ARNT and Sim),encompasses 200-300 amino acids containing two loosely conserved,largely hydrophobic regions approximately 50 amino acids, designated PASA and PAS B. The HIF-1α subunit is unstable during normoxic conditions,overexpression of this subunit in cultured cells under normal oxygenlevels is capable of inducing expression of genes normally induced byhypoxia. An alternative strategy would be to modify the HIF-1α subunitsuch that it no longer is destabilized by normoxic conditions and wouldtherefore be more potent under a range of oxygen conditions. Replacementof the C terminal (or transactivation) region of the hypoxia-induciblefactor protein with a strong transactivation domain from atranscriptional activator protein such as, for example, Herpes SimplexVirus (HSV) VP16, NFκB or yeast transcription factors GAL4 and GCN4, isdesigned to stabilize the protein under normoxic conditions and providestrong, constitutive, transcriptional activation. To stabilize thehypoxia-inducible factor protein under normoxic conditions and toprovide strong, constitutive transcriptional activation, ahybrid/chimeric fusion protein consisting of the DNA-binding anddimerization domains from HIF-1α and the transactivation domain fromHerpes Simplex Virus (HSV) VP16 protein was constructed. Administrationof this hybrid/chimera to the cells of a subject via gene therapyinduces the expression of genes normally up-regulated in response tohypoxia (i.e., VEGF and the like). A constitutively stable hybrid HIF-1α has been shown to be effective for treating ischemic patients (U.S.Patents Nos. 6,432,927 and 7,053,062, both of which are incorporated byreference herein in their entirety).

Members of the vascular endothelial growth factor (VEGF) family areamong the most powerful modulators of vascular biology. They regulatevasculogenesis, angiogenesis, and vascular maintenance. VEGF165 is onesuch member of the VEGF family that may be used in the instantinvention.

The molecular basis of spinal muscular atrophy (SMA), an autosomalrecessive neuromuscular disorder, is the homozygous loss of the survivalmotor neuron gene 1 (SMN1). A nearly identical copy of the SMN1 gene,called SMN2, modulates the disease severity. The functional differencebetween both genes is a translationally silent mutation that, however,disrupts an exonic splicing enhancer causing exon 7 skipping in mostSMN2 transcripts. Only 10% of SMN2 transcripts encode functionalfull-length protein identical to SMN1. SMN protein plays awell-established role in assembly of the spliceosome and may alsomediate mRNA trafficking in the axon and nerve terminus of neurons.

CNTF (Ciliary neurotrophic factor) is a neurocytokine expressed by glialcells in peripheral nerves and the central nervous system. CNTF isgenerally recognized for its function in support and survival ofnon-neuronal and neuronal cell types. See e.g., Vergara, C and Ramirez,B; Brain Res, Brain Res. Rev. 2004; 47: 161-73.

Sonic hedgehog (Shh) controls important developmental processes,including neuronal and glial cell survival.

Erythropoietin (EPO) is a principal regulator of erythroid progenitorcells. However, it is functionally expressed in the nervous system andhas been reported to have a neuroprotective effects. See e.g.,Bartesaghi, S., 2005. Neurotoxicology, 26:923-8.

Lysyl oxidase (LOX) oxidizes the side chain of peptidyl lysine therebyconverting certain lysine residues toalpha-aminoadipic-delta-semialdehyde. This is a post-translationalchange that, for example, enables the covalent cross-linking of thecomponent chains of collagen and elastin. It stabilizes the fibrousdeposits of these proteins in the extracellular matrix. LOX can alsooxidize lysine within a variety of cationic proteins, which suggeststhat its functions are broader than stabilization or the extracellularmatrix. LOX is synthesized as a preprotein; it emerges from the cell asproLOX and is processed proteolytically to the active enzyme. See e.g.,Lucero, HA and Kagan, HM, Cell Mol. Life Sci. 2006; 63(19-20):2304-16.

Progranulin (PGRN) is a pleitropic protein that has gained the attentionof the neuroscience community with the recent discoveries of mutationsin the gene that cause frontotemporal lobar degeneration. PGRN in thecentral nervous system is expressed by microglia and neurons and plays arole in brain development. PGRN is also involved in multiple “tissuemodeling” processes including development, wound repair andtumorogenesis. PGRN is converted to Granulin (GRN) by elastase enzymes.While progranulin has trophic properties, GRNs are more akin toinflammatory mediators. Gene expression studies from animal models ofCNS disease show a differential increase in PRGN combined withmicroglial activation and inflammation. Suggestion that the increase inPGRN expression is closely related to microglial activation andneuroinflammation. Moreover, PGRN expression is increased in activatedmicroglia in many neurodegenerative diseases including motor neurondisease and Alzheimer’s disease. Studies have identified mutations inPGRN as a cause of neurodegenerative disease and indicate the importanceof PGRN function for neuronal survival.

Prolactin and placenta lactogen: Oligodendrocytes, the myelinating cellsof the CNS, continue to be generated by oligodendrocyte precursor cells(OPCs) throughout adulthood (Gensert and Goldman, 1997; Levison et al.,1999; Menn et al., 2006; Peters and Sethares, 2004) and are required forthe intrinsic repair of myelin damage in the adult CNS (Polito andReynolds, 2005). The physiological events that modulate OPCproliferation and the generation of new myelinating oligodendrocytes inthe adult CNS are largely known.

Recently it has been reported that patients with Multiple Sclerosis, ademyleinating disease, have a reduced relapse rate during the 3rdtrimester of pregnancy suggesting that hormones influenceoligodendrocyte generation (Confavreux et al., 1998; Voskuhl, 2003).Remission in MS patients is correlated with a decrease in the number andsize of active white matter lesions (van Walderveen et al., 1994).Interestingly, pregnancy in mice results in an increase in thegeneration of new oligodendrocytes and the number of myelinated axonswithin the maternal CNS (Gregg et al., 2007). Prolactin, a hormone thatplateaus during the final stage of pregnancy, has been shown to regulateOPC proliferation during pregnancy and promote white matter repair invirgin female mice (Gregg et al., 2007).

There is reason to believe that human placenta lactogen (hPL), a hormonethat also peaks during the 3rd trimester of pregnancy (Selenkow et al.,1969), may have a similar influence on oligodendrocyte generation. hPLhas a number of biological activities that are qualitatively similar tohuman growth hormone (hGH) and prolactin (Lesniak et al., 1977) andappears to be a major regulator of IGF-1 production (Handwerger et al.,1992; Zimkeller, 2000; Handwerger et al., 2000). Both hGH and IGF-1 havebeen shown to be stimulators of myelination in the adult CNS (Carson etal., 1993; Peltwon et al., 1977). Therefore, the treatment of CNSdiseases involving demyelination such as MS, ALS, stroke and spinal cordinjury may benefit from PRL or hPL based therapies intraventricularinjection of an rhPRL or hPL expressing viral vector.

Ghrelin is a gastric hormone that was recognized in 1999 as a mediatorof growth hormone release. See e.g. Wu, JT et al., 2004; Ann. Surg.239:464.

Neuroserpin is a serpin protease inhibitor family member. In certaincentral nervous system conditions, neuroserpin can play aneuroprotective role potentially through the blockage of the effects oftPA. See, e.g., Galliciotti, G and Sonderegger, P, 2006, Front Biosci11: 33; Simonin, Y et al., 2006, J Neurosci; 26:10614; Miranda, E andLomas, DA, 2006, Cell Mol Life Sci 63:709.

Angiogenin is a member of the RNAse superfamily. It is a normalconstituent of circulation but has also been implicated as a risk factorin motor neuron disorders.

Without being limited as to theory, IGF-1 is a therapeutic protein forthe treatment of ALS due to its many actions at different levels ofneuraxis (see Dore et al., Trends Neurosci, 1997, 20:326-331). In thebrain: It is thought to reduce both neuronal and glial apoptosis,protect neurons against toxicity induced by iron, colchicine, calciumdestabilizers, peroxides, and cytokines. It also is thought to modulatethe release of neurotransmitters acetylcholine and glutamate. It is alsothought to induce the expression of neurofilament, tublin, and myelinbasic protein. In the spinal cord: IGF-1 is thought to modulate ChATactivity and attenuate loss of cholinergic phenotype, enhance motorneuron sprouting, increase myelination, inhibit demyelination, stimulatemotor neuron proliferation and differentiation from precursor cells, andpromote Schwann cell division, maturation, and growth. In the muscle:IGF-1 is thought to induce acetylcholine receptor cluster formation atthe neuromuscular junction and increase neuromuscular function andmuscle strength.

The level of transgene expression in eukaryotic cells is largelydetermined by the transcriptional promoter within the transgeneexpression cassette. Promoters that show long-term activity and aretissue- and even cell-specific are used in some embodiments. Nonlimiting examples of promoters include, but are not limited to, thecytomegalovirus (CMV) promoter (Kaplitt et al. (1994) Nat. Genet.8:148-154), CMV/human β3-globin promoter (Mandel et al. (1998) J.Neurosci. 18:4271-4284), GFAP promoter (Xu et al. (2001) Gene Ther.8:1323-1332), the 1.8-kb neuron-specific enolase (NSE) promoter (Kleinet al. (1998) Exp. Neurol. 150:183-194), chicken beta actin (CBA)promoter (Miyazaki (1989) Gene 79:269-277), the β-glucuronidasε (GUSB)promoter (Shipley et al. (1991) Genetics 18:1009-1018), and ubiquitinpromoters such as those isolated from human ubiquitin A, human ubiquitinB, and human ubiquitin C as described in US Patent No. 6,667,174. Toprolong expression, other regulatory elements may additionally beoperably linked to the transgene, such as, e.g., the Woodchuck HepatitisVirus Post-Regulatory Element (WPRE) (Donello et al. (1998) J. Virol.72:5085-5092) or the bovine growth hormone (BGH) polyadenylation site.

For some CNS gene therapy applications, it may be necessary to controltranscriptional activity. To this end, pharmacological regulation ofgene expression with viral vectors can been obtained by includingvarious regulatory elements and drug-responsive promoters as described,for example, in Habermaet al. (1998) Gene Ther. 5:1604-16011; and Ye etal. (1995) Science 283:88-91.

In certain embodiments, the concentration or titer of the vector in thecomposition is at least: (a) 5, 6,7,8,9, 10, 15,20,25, or 50 (×10¹²gp/ml); (b) 5, 6,7, 8,9, 10, 15,20, 25, or 50 (× 10⁹ tu/ml); or (c) 5,6,7,8,9, 10, 15, 20, 25, or 50 (× 10¹⁰ iu/ml).

In one aspect, the transgene encodes a biologically active molecule,expression of which in the CNS results in at least partial correction ofneuropathology and/or stabilization of disease progression. In someembodiments, the therapeutic transgene product is an IGF-1 protein thatalleviates and/or prevents the symptoms of ALS. See Roaul et al. (2005)Nat. Med. 1 1(4):423-428 and Ralph et al. (2005) Nat. Med.11(4):429-433. In other aspects, two transgenes are encoded, for exampleIGF-1 and VEGF, expression of which in the CNS results in at leastpartial correction of neuropathology such as alleviation and/orprevention and/or stabilization and/or slowing the progression of thesymptoms of ALS.

In one aspect when performing these methods, the transgene expresses atherapeutic amount of insulin growth factor-1 (IGF-1), calbindin D28,parvalbumin, HIF1-alpha, SIRT-2, VEGF, SMN-1, SMN-2, CNTF (Ciliaryneurotrophic factor), sonic hedgehog (shh), erythropoietin (EPO), lysyloxidase (LOX), progranulin, prolactin, ghrelin, neuroserpin, angiogenin,and placenta lactogen.

For identification of structures in the human brain, see, e.g., TheHuman Brain: Surface, Three-Dimensional Sectional Anatomy With MRI, andBlood Supply, 2nd ed., eds. Deuteron et al., Springer Vela, 1999; Atlasof the Human Brain, eds. Mai et al., Academic Press; 1997; and Co-PlanarStereotaxic Atlas of the Human Brain: 3-Dimensional Proportional System:An Approach to Cerebral Imaging, eds. Tamarack et al., Thyme MedicalPub., 1988. For identification of structures in the mouse brain, see,e.g., The Mouse Brain in Stereotaxic Coordinates, 2nd ed., AcademicPress, 2000.

To deliver the solution or other composition containing the viral vectorspecifically to a particular region of the central nervous system, suchas to a particular ventricle, e.g., to the lateral ventricles or to thefourth ventricle of the brain, it may be administered by stereotaxicmicroinjection. For example, on the day of surgery, patients will havethe stereotaxic frame base fixed in place (screwed into the skull). Thebrain with stereotaxic frame base (MRI-compatible with fiduciarymarkings) will be imaged using high resolution MRI. The MRI images willthen be transferred to a computer that runs stereotaxic software. Aseries of coronal, sagittal and axial images will be used to determinethe target site of vector injection, and trajectory. The softwaredirectly translates the trajectory into 3-dimensional coordinatesappropriate for the stereotaxic frame. Burr holes are drilled above theentry site and the stereotaxic apparatus localized with the needleimplanted at the given depth. The vector solution in a pharmaceuticallyacceptable carrier will then be injected. Additional routes ofadministration may be used, e.g., superficial cortical application underdirect visualization, or other non-stereotaxic application.

One way for delivering the viral vector is to use a pump. Such pumps arecommercially available, for example, from Alzet (Cupertino, CA) orMedtronic (Minneapolis, MN). The pump may be implantable. Anotherconvenient way to administer the vector is to use a cannula or acatheter.

The subject invention provides methods to modulate, correct or augmentmotor function in a subject afflicted with motor neuronal damage. Forthe purpose of illustration only, the subject may suffer from one ormore of amytrophic lateral sclerosis (ALS), spinal bulbar muscularatrophy, spinal muscular atrophy, spinal cerebellar ataxia, primarylateral sclerosis (PLS), or traumatic spinal cord injury.

Without being limited as to theory, the pathology associated with motorneuron damage may include motor neuron degeneration, gliosis,neurofilament abnormalities, loss of myelinated fibers in corticospinaltracts and ventral roots. Two types of onset are recognized: bulbaronset, which affects brainstem motor neurons,(affects the facialmuscles, speech, and swallowing); and limb onset, which affects spinalcord motor neurons, is reflected by spasticity, generalized weakness,muscular atrophy, paralysis, and respiratory failure. In ALS, subjectshave both bulbar and limb onset. In PLS, subjects have bulbar onset.

The ability to organize and execute complex motor acts depends onsignals from the motor areas in the cerebral cortex, i.e., the motorcortex. Cortical motor commands descend in two tracts. The corticobularfibers control the motor nuclei in the brain stem that move facialmuscles and the corticospinal fibers control the spinal motor neuronsthat innervate the trunk and limb muscles. The cerebral cortex alsoindirectly influences spinal motor activity by acting on the descendingbrain stem pathways.

The primary motor cortex lies along the precentral gyrus in Broadmann’sarea (4). The axons of the cortical neurons that project to the spinalcord run together in the corticospinal tract, a massive bundle of fiberscontaining about 1 million axons. About a third of these originate fromthe precentral gyrus of the frontal lobe. Another third originate fromarea 6. The remainder originates in areas 3, 2, and 1 in the somaticsensory cortex and regulate transmission of afferent input through thedorsal horn.

The corticospinal fibers run together with corticobulbar fibers throughthe posterior limb of the internal capsule to reach the ventral portionof the midbrain. They separate in the pons into small bundles of fibersthat course between the pontine nuclei. They regroup in the medulla toform the medullary pyramid. About three-quarters of the corticospinalfibers cross the midline in the pyramidal decussation at the junction ofthe medulla and spinal cord. The crossed fibers descend in the dorsalpart of the lateral columns (dorsolateral column) of the spinal cord,forming the lateral corticospinal tract. The uncrossed fibers descend inthe ventral columns as the ventral corticospinal tract.

The lateral and ventral divisions of the corticospinal tract terminatein about the same regions of spinal gray matter as the lateral andmedial systems of the brain stem. The lateral corticospinal tractprojects primarily to motor nuclei in the lateral part of the ventralhorn and to interneurons in the intermediate zone. The ventralcorticospinal tract projects bilaterally to the ventromedial cell columnand to adjoining portions of the intermediate zone that contain themotor neuorons that innervate axial muscles.

If desired, the human brain structure can be correlated to similarstructures in the brain of another mammal. For example, most mammals,including humans and rodents, show a similar topographical organizationof the entorhinal-hippocampus projections, with neurons in the lateralpart of both the lateral and medial entorhinal cortex projecting to thedorsal part or septal pole of the hippocampus, whereas the projection tothe ventral hippocampus originates primarily from neurons in medialparts of the entorhinal cortex (Principles of Neural Science, 4th ed.,eds Kandel et al., McGraw-Hill, 1991; The Rat Nervous System, 2nd ed.,ed. Paxinos, Academic Press, 1995). Furthermore, layer II cells of theentorhinal cortex project to the dentate gyrus, and they terminate inthe outer two-thirds of the molecular layer of the dentate gyrus. Theaxons from layer III cells project bilaterally to the cornu ammonisareas CA1 and CA3 of the hippocampus, terminating in the stratumlacunose molecular layer.

In one aspect, the disclosed methods include administering to the CNS ofan afflicted subject a neurotrophic viral vector carrying a transgeneencoding a therapeutic product and allowing the transgene to beexpressed within the CNS near the administration site at a levelsufficient to exert a therapeutic effect as the expressed protein istransported via the CSF throughout the CNS. In addition, the vector maycomprise a polynucleotide encoding for a biologically active moleculeeffective to treat the CNS disorder. Such biologically active moleculesmay comprise peptides including but not limited to native or mutatedversions of full-length proteins, native or mutated versions of proteinfragments, synthetic polypeptides.

In an illustrative embodiment, the administration is accomplished bydirect injection of a high titer vector solution into one or more of theventricular spaces of the brain, such as the lateral ventricle of asubject or patient. For example, the administration is by direct bolusinjection into one or more ventricles of the brain such as the lateraland fourth ventricles.

In some embodiments, the methods comprise administration of a high titerneurotrophic vector carrying a therapeutic transgene so that thetransgene product is expressed at a therapeutic level at a first sitewithin theCNS distal to the ultimate siteof action of the expressedproduct. In some embodiments, the viral titer of the composition is atleast: (a) 5, 6, 7, 8, 9, 10, 15, 20, 25, or 50 (x10¹² gp/ml); (b) 5, 6,7, 8, 9, 10, 15, 20, 25, or 50 (x10⁹ tu/ml); or (c) 5, 6, 7, 8, 9, 10,15, 20, 25, or 50 (x10¹⁰ iu/ml).

In experimental mice, the total volume of injected AAV solution is forexample, between 1 to 20 µl. For other mammals, including the humanbrain, volumes and delivery rates are appropriately scaled. For example,it has been demonstrated that volumes of 150 µl can be safely injectedin the primate brain (Janson et al. (2002) Hunt. Gene Ther.13:1391-1412). Treatment may consist of a single injection per targetsite, or may be repeated in one or more ventricles. Suitable ventriclesinclude the lateral ventricles, third ventricle, and the fourthventricle. Multiple injection sites can be used. For example, in someembodiments, in addition to the first administration site, a compositioncontaining a viral vector carrying a transgene is administered toanother site which can be contralateral or ipsilateral to the firstadministration site. Injections can be single or multiple, unilateral orbilateral.

High titer AAV preparations can be produced using techniques known inthe art, e.g., as described in United States Patent No. 5,658,776 andViral Vectors for Gene Therapy: Methods and Protocols, ed. Machida,Humana Press, 2003.

The following examples provide illustrative embodiments of theinvention. One of ordinary skill in the art will recognize the numerousmodifications and variations that may be performed without altering thespirit or scope of the present invention. Such modifications andvariations are encompassed within the scope of the invention. Theexamples do not in any way limit the invention.

EXAMPLES Titration of Recombinant Vectors

AAV vector titers are measured according to genome copy number (genomeparticles per milliliter). Genome particle concentrations are based onTagman® PCR of the vector DNA as previously reported (Clark et al.(1999) Hum. Gene Ther., 10:1031-1039; Veldwijk et al. (2002) Mol. Ther.,6:272-278).

Vectors carrying an assayable marker gene such as the β-galactosidase(Lac Z) or green fluorescent protein gene (GFP) can be titered using aninfectivity assay. Susceptible cells (e.g., HeLa, or COS cells) aretransduced with the AAV and an assay is performed to determine geneexpression such as staining of β-galactosidase vector-transduced cellswith X-gal (5-bromo-4chloro- 3-indolyl-β-D-galactopyranoside) orfluorescence microscopy for GFP-transduced cells. For example, the assayis performed as follows: 4 x10⁴ HeLa cells are plated in each well of a24-well culture plate using normal growth media. After attachment, i.e.,about 24 hours later, the cells are infected with Ad type 5 at amultiplicity of infection (MOI) of 10 and transduced with serialdilutions of the packaged vector and incubated at 37° C. One to threedays later, before extensive cytopathic effects are observed, theappropriate assay is performed on the cells (e.g., X-gal staining orfluorescence microscopy). If a reporter gene such as β-galactosidase isused, the cells are fixed in 2% paraformaldehyde, 0.5% glutaraldehydeand stained for β-galactosidase activity using X-gal. Vector dilutionsthat give well-separated cells are counted. Each positive cellrepresents 1 transduction unit (tu) of vector.

Therapeutically Relevant Model of Amyotrophic Lateral Sclerosis (ALS)

Amytrophic lateral sclerosis (ALS) is a fatal neurodegenerative diseasethat is characterized by a selective loss of motorneurons in the cortex,brain stem and spinal cord. Progression of the disease can lead toatrophy of limb, axial and respiratory muscles. Motor neuron cell deathis accompanied by reactive gliosis, neurofilament abnormalities, and asignificant loss of large myelinated fibers in the corticospinal tractsand ventral roots¹⁻⁶. Although the etiology of ALS is poorly understood,accumulating evidence indicates that sporadic (SALS) and familial (FALS)ALS share many similar pathological features; thus, providing a hopethat the study of either form will lead to a common treatment ⁷. FALSaccounts for approximately 10% of diagnosed cases, of which 20% areassociated with dominantly inherited mutations in Cu/Zn superoxidedismutase (SOD1) ⁸. Transgenic mice that express the mutant human SOD1protein (e.g., SOD1^(G93A) mice) recapitulate many pathological featuresof ALS and are an available animal model to study ALS ⁹. For SALS, amyriad of pathological mechanisms have been implicated as the underlyingcause, including glutamate induced excitotoxicity, toxin exposure,proteasome dysfunction, mitochondrial damage, neurofilamentdisorganization and loss of neurotrophic support ^(10,11).

To date there is no effective therapy for the treatment of ALS.Neurotrophic factors such as insulin growth factor I (IGF-1) have beeninvestigated extensively for their potential usefulness in the treatmentof ALS. Intracranial delivery of viral vectors to regions of the CNSthat are interconnected with brainstem and spinal motor neurons via theCSF provides a means of administering potential therapeutics, such asIGF-1, to areas that would otherwise be difficult to target throughprior art means.

Without being limited as to theory, IGF-1 is a therapeutic protein forthe treatment of ALS due to its many actions at different levels ofneuraxis (see Dore et al., Trends Neurosci, 1997, 20:326-331). In thebrain: It is thought to reduce both neuronal and glial apoptosis,protect neurons against toxicity induced by iron, colchicine, calciumdestabilizers, peroxides, and cytokines. It also is thought to modulatethe release of neurotransmitters acetylcholine and glutamate. It is alsothought to induce the expression of neurofilament, tublin, and myelinbasic protein. In the spinal cord: IGF-1 is thought to modulate ChATactivity and attenuate loss of cholinergic phenotype, enhance motorneuron sprouting, increase myelination, inhibit demyelination, stimulatemotor neuron proliferation and differentiation from precursor cells, andpromote Schwann cell division, maturation, and growth. In the muscle:IGF-1 is thought to induce acetylcholine receptor cluster formation atthe neuromuscular junction and increase neuromuscular function andmuscle strength. In the following experiments, the IGF-1 Ea form of theprotein was utilized.

Example 1: Intracerebroventricular Delivery of AAV4-IGF-1,

We conducted experiments to determine if intraventricular delivery ofAAV4-IGF-1 led to (1) significant extension of lifespan; (2) improvedperformance on rotarod and grip strength tasks; and (3) reducedneuropathology (i.e., alleviation in gliosis and improved motor neuronsurvival) in the brainstem and spinal cord.

Symptomatic SOD1 mice (i.e., 90 days old) were treated either withAAV4-IGF-1 or AAV4-Bgal control vector (Bgal is also referred to as LacZ). For each mouse, vectors were injected into both the lateral (A-P:-.3 from bregma, M-L: -1.0 from bregma, D-V: -2.0 from dura, incisorbar: 0.0) and the 4th ventricle (A-P: -5.90 from bregma, M-L: 0.0 frombregma, D-V: -2.9 from dura, incisor bar: 0.0) using a stereotaxicframe. Vectors were delivered with a 10µl Hamilton syringe at a rate of0.5 µl/minute for a total of 1.80 x 1010 genome copies per ventricle.The final injection volume for each vector was 10 µl/ventricle. At age110 days or at end stage, 4 mice from each treatment group weresacrificed for histological analysis (i.e., GFAP (glial fibrillaryacidic protein) staining and MN counts in the brainstem and spinalcord). End points which have been evaluated include survival analysis,rotarod, hindlimb and forelimb grip strength tests, and body mass.

Testing of motor function using a rotarod device and Grip Strength Meter(Columbus Instruments, Columbus, OH) can begin at 70 days of age. Eachweekly session may consist of three trials on the elevated acceleratingrotarod beginning at 5 rpm/min. The time each mouse remains on the rodcan be registered automatically. Grip strength meter testing can beperformed by allowing the animals to grasp a platform followed bypulling the animal until it releases the platform: the force measurementis recorded in four separate trials. Onset of disease-related weaknessis defined when one hindlimb displayed muscle weakness and limb draggingon the rotarod, as assessed by two independent observers. To determinemortality in a reliable and humane fashion, we use an artificial endpoint defined by the inability of mice to right themselves 30 secondsafter being placed on their sides.

Intracerebroventricular delivery of AAV4-IGF-1 resulted in a significantextension of lifespan in SOD1 mice as compared to mice receivingAAV4-Bgal as a control vector. Mice receiving AAV4-IGF1 had a mediansurvival time of 141.5 days as compared to a median survival time of 121days in mice treated with AAV4-Bgal (FIG. 1 ). SOD1 mice treated withAAV4-IGF-1 had improved functional outcomes as measured by Rotarodtesting, forelimb grip strength, and hindlimb grip strength as comparedto control-treated mice. Results are shown in FIGS. 1-5 .

Histological assessment of GFAP, which is a marker of gliosis and apathological hallmark of ALS, demonstrated that astrogliosis wassignificantly reduced in mice treated with AAV4-IGF1 as compared tocontrol mice treated with AAV4-Bgal. This reduction was observed in boththe brainstem region of the CNS (e.g., trigeminal nucleus, facialnucleus, hypoglossal nucleus; FIG. 6 ) and the ventral spinal cord(e.g., cervical, thoracic, lumbar, sacral; FIG. 7 ).

Histological assessment of nitrotyrosine levels, which is a marker ofperoxynitrite and a pathological marker associated with ALS,demonstrated that nitrotyrosine levels were significantly reduced inmice treated with AAV4-IGF1 as compared to control mice treated withAAV4-Bgal. This reduction in nitrotyrosine levels was observedthroughout the spinal cord, e.g., cervical, thoracic, lumbar, and sacralregions (FIG. 8 ).

Example 2: Intracerebroventricular Delivery of AAV4-IGF-1 and AAV4-GFP

Symptomatic SOD1 mice (i.e., 88-90 days old) were treated either withAAV4-IGF-1 or AAV4-GFP vector via intracerebroventricular injection ofthe vector into both the lateral and the 4th ventricle. Mice received adose of 2 e10 gc/ventricle. Green fluorescent protein was utilized as acontrol protein, which enabled the visualization of expression mediatedby the injection of the AAV vectors.

The end points evaluated included survival, rotarod testing, gripstrength (hindlimb and forelimb), motor neuron cell counts, GFP proteindistribution, glial fibrillary acidic protein (GFAP) levels,nitrotyrosine levels, and RT-PCR to measure viral distribution withinthe CNS. At age 110 days or at end stage, mice from each treatment groupwere sacrificed for additional analysis. Glial fibrillary acidic protein(GFAP) levels were evaluated histologically. GFAP is a marker ofgliosis, which is a pathological hallmark of ALS. Nitrotyrosine levelswere evaluated histologically; nitrotyrosine is a marker ofperoxynitrite.

Intracerebroventricular delivery of AAV4-IGF-1 resulted in a significantextension of lifespan in SOD1 mice as compared to mice receivingAAV4-GFP as a control vector. SOD1 mice treated with AAV4-IGF-1 hadimproved functional outcomes as measured by Rotarod testing, forelimbgrip strength, and hindlimb grip strength as compared to control-treatedmice.

Visualization of green fluorescent protein (GFP) expression in mice thathad been treated with AAV4-GFP indicated that GFP was distributedthroughout the ependymal cell layer of the ventricular system. Forexample, GFP was visualized in the anterior lateral ventricles, thelateral ventricles, the third ventricle, and the fourth ventricle (FIG.9 ). GFP was also visualized in the choroid plexus of the ventricularsystem and the ependymal cell layer of the spinal cord central canal(including the cervical, thoracic, and lumbar regions) (FIG. 10 ).

RT-PCR for the AA V4-IGF-1 vector demonstrated that vector was presentin the cortex, brainstem, and spinal cord following intraventriculardelivery (FIG. 11A).

Example 3: Intracerebroventricular Delivery of AAV4-VEGF and AAV4-GFP

Symptomatic SOD1 mice (i.e., 88-90 days old) were treated either withAAV4-VEGF-165 or AAV4-GFP vector via intracerebroventricular injectionof the vector into both the lateral and the 4th ventricle. Mice receiveda dose of 2 e10 gc/ventricle. Green fluorescent protein was utilized asa control protein, which enabled the visualization of expressionmediated by the injection of the AAV vectors.

The end points evaluated included survival, rotarod testing, gripstrength (hindlimb and forelimb), and RT-PCR to measure viraldistribution within the CNS.

Intracerebroventricular delivery of AAV4-VEGF resulted in a significantextension of lifespan in SOD1 mice as compared to mice receivingAAV4-GFP as a control vector. Median survival times for mice receivingAAV4-VEGF was 140 days whereas median survival times for mice receivingAAV4-GFP was 120 days (FIG. 12 ).

SOD1 mice treated with AAV4-VEGF had improved functional outcomes asmeasured by Rotarod testing (FIG. 13 ), forelimb grip strength andhindlimb grip strength (FIG. 13 ) as compared to control-treated mice.

Intraventricular delivery of AAV4-VEGF did not influence body mass inSOD1 mice.

RT-PCR for the AAV4-IGF-1 vector demonstrated that vector was present inthe cortex, brainstem, and spinal cord following intraventriculardelivery (FIG. 11B).

The specification is most thoroughly understood in light of theteachings of the references cited within the specification. Theembodiments within the specification provide an illustration ofembodiments of the invention and should not be construed to limit thescope of the invention. The skilled artisan readily recognizes that manyother embodiments are encompassed by the invention. All publications,patents, and biological sequences cited in this disclosure areincorporated by reference in their entirety. To the extent the materialincorporated by reference contradicts or is inconsistent with thepresent specification, the present specification will supercede any suchmaterial. The citation of any references herein is not an admission thatsuch references are prior art to the present invention.

Unless otherwise indicated, all numbers expressing quantities ofingredients, cell culture, treatment conditions, and so forth used inthe specification, including claims, are to be understood as beingmodified in all instances by the term “about.” Accordingly, unlessotherwise indicated to the contrary, the numerical parameters areapproximations and may very depending upon the desired properties soughtto be obtained by the present invention. Unless otherwise indicated, theterm “at least” preceding a series of elements is to be understood torefer to every element in the series. Those skilled in the art willrecognize, or be able to ascertain using no more than routineexperimentation, many equivalents to the specific embodiments of theinvention described herein. Such equivalents are intended to beencompassed by the following claims.

TABLE 1 Potential gene pairs for use in a recombinant viral vector GeneIGF-1 calbindin D28 Parvalbumin HIF1-alpha SIRT-2 CNTF IGF-1 X X X X Xcalbindin D28 X X X X X parvalbumin X X X X X HIF1-alpha X X X X XSIRT-2 X X X X X VEGF X X X X X X SMN-1 X X X X X X SMN-2 X X X X X XCNTF X X X X X shh X X X X X X EPO X X X X X X LOX X X X X X Xprogranulin X X X X X X prolactin X X X X X X placenta lactogen X X X XX X ghrelin X X X X X X angiogenin X X X X X X neuroserpin X X X X X X

TABLE 2 Potential gene pairs for use in a recombinant viral vector Geneprogranulin prolactin placenta lactogen ghrehlin angiogenin IGF-1 X X XX X calbindin D28 X X X X X parvalbumin X X X X X H1F1-alpha X X X X XSIRT-2 X X X X X VEGF X X X X X SMN-1 X X X X X SMN-2 X X X X X CNTF X XX X X shh X X X X X EPO X X X X X LOX X X X X X progranulin X X X Xprolactin X X X X placenta lactogen X X X X ghrelin X X X X angiogenin XX X X neuroserpin X X X X X

TABLE 3 Potential gene pairs for use in a recombinant viral vector Geneshh EPO LOX VEGF SMN-1 SMN-2 neuroserpin IGF-1 X X X X X X X calbindinD28 X X X X X X X parvalbumin X X X X X X X HIF1-alpha X X X X X X XSIRT-2 X X X X X X X VEGF X X X X X X SMN-1 X X X X X X SMN-2 X X X X XX CNTF X X X X X X X shh X X X X X X EPO X X X X X X LOX X X X X X Xprogranulin X X X X X X X prolactin X X X X X X X placenta lactogen X XX X X X X ghrelin X X X X X X X angiogenin X X X X X X X neuroserpin X XX X X X

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We claim: 1-9. (canceled)
 10. A method to treat amyotrophic lateralsclerosis (ALS) in a subject, comprising administering a recombinantneurotrophic viral vector comprising a therapeutic transgene to at leastone ventricle of the brain, whereby said transgene is expressed in atherapeutically effective amount; wherein the transgene is VEGF and theviral vector is an adeno-associated (AAV) vector.
 11. (canceled)
 12. Themethod of claim 10 wherein the viral vector is AAV4.
 13. (canceled) 14.The method of claim 10 wherein the viral vector is administered bydirect injection into a ventricle of the brain.
 15. The method of claim10 wherein the viral vector is administered by direct injection into alateral ventricle of the brain.
 16. The method of claim 10 wherein theviral vector is administered by direct injection into the fourthventricle of the brain. 17-20. (canceled)
 21. The method of claim 10wherein said subject is a mammal.
 22. The method of claim 21, whereinsaid mammal is selected from the group consisting of a rodent, a murine,a simian, and a human.
 23. The method of claim 10, wherein said subjectis a human patient. 24-30. (canceled)
 31. The method of claim 10,wherein the viral vector is administered by direct injection into both alateral ventricle of the brain and the fourth ventricle of the brain.32. A method to treat amyotrophic lateral sclerosis in a human subject,comprising administering a recombinant AAV4 viral vector comprising aVEGF transgene to at least one ventricle of the brain selected from thegroup consisting of a lateral ventricle and the fourth ventricle,whereby said VEGF transgene is expressed in a therapeutically effectiveamount.